Harper Lee — the Alabama author whose book To Kill a Mockingbird, exploring racism and prejudice in the Deep South, is regarded as one of the greatest novels ever written — died Friday at age 89.

The mayor's office of Monroeville, Alabama, Lee's hometown, confirmed her death to BuzzFeed News. It was first reported by AL.com.

Though she didn't publish another book for over half a century after Mockingbird was released in 1960, Lee was viewed as one of the giants of American literature.

"She lived her life the way she wanted to — in private — surrounded by books and the people who loved her. I will always cherish the time I spent with her,” said Michael Morrison, President and Publisher, U.S. General Books and Canada at HarperCollins.

President Obama on Friday described Lee as a "country girl who just wanted to tell an honest story":

"But what that one story did, more powerfully than one hundred speeches possibly could, was change the way we saw each other, and then the way we saw ourselves. Through the uncorrupted eyes of a child, she showed us the beautiful complexity of our common humanity, and the importance of striving for justice in our own lives, our communities, and our country. Ms. Lee changed America for the better.

Her agent, Andrew Nurnberg, said that when he saw her six weeks ago, she was "full of life" and her mind and "mischievous wit as sharp as ever."

"She was quoting Thomas More and setting me straight on Tudor history," he said. "We have lost a great writer, a great friend and a beacon of integrity."

Lee's novel was studied by school students the world over and reprinted tens of millions of times. She won the Pulitzer Prize for Literature in 1961, and was honored by President George W. Bush in 2007 with the Presidential Medal of Freedom and by Obama in 2010 with the National Medal of Arts for her contributions to literature.

After withdrawing from public life for decades, Lee surprised the literary world by publishing her second novel, Go Set a Watchman, in 2015. The enormous excitement around the release of the book, which followed the same beloved characters from Mockingbird some two decades later, was a testament to the central place Lee's first novel occupied in the American literary canon — and in the hearts of readers.

"A hundred pounds of sermons on tolerance, or an equal measure of invective deploring the lack of it, will weigh far less in the scale of enlightenment than a mere 18 ounces of a new fiction bearing the title To Kill a Mockingbird," read the Washington Post review of the novel upon its release.

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Nelle Harper Lee was born April 28, 1926, in Monroeville, a small town that would prove formative in her writing and which was, in 1997, officially proclaimed by Alabama lawmakers to be the state's literary capital, having also played home to a young Truman Capote.

"In my hometown, a remote village in the early 1930s, youngsters had little to do but read," Lee wrote in a letter to Oprah Winfrey for the talk show host's magazine in 2006. "A movie? Not often — movies weren't for small children. A park for games? Not a hope. We're talking unpaved streets here, and the Depression."

"Do you remember when you learned to read, or like me, can you not even remember a time when you didn't know how?" she wrote, recalling being read daily stories from her mother, Frances Finch, while her lawyer father, Amasa Coleman Lee, would read to her from "the four newspapers he got through every evening."

Lee in 1963.

Like her father, she went on to study law at the University of Alabama, but left for New York in 1949 before completing a degree. With dreams of pursuing a literary career, she wrote in her spare time while working as an airline reservations clerk.

In 1957 she delivered a manuscript for Watchman to her literary agent, who sold it on to the publishing house J. B. Lippincott Company. Her editor, Therese von Hohoff Torrey, immediately sensed the makings of a rare talent, but worked with Lee on reimagining the work through a series of drafts. “I was a first-time writer, so I did as I was told,” Lee later said. Frustrated by her own attempts to reshape the book, Lee at one stage was said to have tearfully thrown the manuscript out the window, before her editor urged her to salvage it from the snowy street.

What emerged was Mockingbird, a novel with the same characters as Watchman but set decades earlier and drastically revised. Set in a fictional Alabama town during the Great Depression, Mockingbird followed the childhood adventures of Jean Louise "Scout" Finch, her brother Jem, and their neighborhood friend Dill Harris, a surrogate for Capote. As the children investigate their myserious neighbor, Boo Radley, Scout and Jem's lionhearted father, Atticus nobly defends a black man falsely accused of raping a white woman.

Full of sage advice for his young daughter, Atticus instantly became an iconic literary paragon of wisdom and virtue. "You never really understand a person until you consider things from his point of view," he tells Scout in one oft-quoted section, "until you climb into his skin and walk around in it.”

Some 80 weeks after its publication, still a national best-seller and a staple of reading lists across the country, the novel won Lee the Pulitzer Prize for Fiction in 1961. A 1991 survey by the Book of the Month Club found Mockingbird ranked second only to the Bible in terms of "making a difference in people's lives."

"It was one of sheer numbness. It was like being hit over the head and knocked cold," Lee said of the novel's enormous success. "I was hoping for a quick and merciful death at the hands of reviewers, but at the same time I sort of hoped that maybe someone would like it enough to give me encouragement. Public encouragement. I hoped for a little, as I said, but I got rather a whole lot, and in some ways this was just about as frightening as the quick, merciful death I'd expected."

A 1962 film version starring Gregory Peck as Atticus further entrenched the novel's place in the canon — while also earning Peck an Oscar. Lee described being unsure initially if Peck was the right choice for the role, but having her doubts immediately put to rest when she saw him in costume during a test on the studio backlot. "It was the most amazing transformation I had ever seen." she told Roy Newquist in 1964. "The minute I saw him I knew everything was going to be all right because he was Atticus.

For decades, Lee was lauded with honorary degrees and inundated with interview requests, but she declined to speak publicly, instead preferring to maintain her privacy and enjoy life in small-town Alabama, alongside her oldest sister, Alice.

“When you have hit the pinnacle, how would you feel about writing more?” Alice Lee told the Chicago Tribune in 2002 of her sister's decision not to write again. “Would you feel like you’re competing with yourself?”

In 2013, Lee sued her literary agent, Samuel Pinkus, for allegedly stealing Mockingbird royalties from her novel, claiming he had taken advantage of her physical disadvantages after she suffered a stroke. The parties settled the lawsuit later that year.

After Alice's death in 2014 at age 103, Lee announced in February 2015 the publication of a second novel, Go Set a Watchman.

In a statement through her publisher at the time, Lee said the work had been recently rediscovered by an old friend and lawyer, Tonja Carter. "After much thought and hesitation, I shared it with a handful of people I trust and was pleased to hear that they considered it worthy of publication," she said. "I am humbled and amazed that this will now be published after all these years."

But the story behind the release of Watchman quickly grew contentious, with some suggesting Lee was not mentally sound or being manipulated by others around her. Alabama officials launched an inquiry into possible financial fraud, but found no evidence of elder abuse. Many, though, were still not satisfied, believing Lee's frailty had been taken advantage of.

Lucas Jackson / Reuters

As the book made its way to shelves, public attention quickly turned to the dramatically different portrait of Atticus Finch that Lee had painted. Watchman, written before Mockingbird, sees Finch return to her hometown as a young women to find her father a cranky old bigot who once attended a Ku Klux Klan meeting.

"The depiction of Atticus in Watchman makes for disturbing reading, and for Mockingbird fans, it’s especially disorienting," New York Times book critic Michiko Kakutani wrote in her review.

Some Mockingbird fans avoided reading the book altogether or debated whether it could indeed be considered a true "sequel," while others who had named their children and pets after Atticus faced an even more awkward dilemma.

The book, while a commercial success, could never possibly have reached the same iconic status as Mockingbird. Atticus Finch, despite Lee's secondary portrait, remains a central figure in American literature — so beloved that not even the author herself can challenge his status.

"One reason To Kill a Mockingbird succeeded is the wise and kind heart of the author, which comes through on every page," President Bush said while awarding Lee the presidential medal in 2007. "This daughter of Monroeville, Alabama, had something to say about honor, and tolerance, and, most of all, love — and it still resonates.

"To Kill a Mockingbird has influenced the character of our country for the better. It's been a gift to the entire world," he said.

For Lee, though, her aspirations were always much smaller.

Speaking to Newquist in 1964, she admitted her objectives as a writer were limited to exploring the small slice of Southern life in which she grew up. "I would like to leave some record of the kind of life that existed in a very small world," she said.

"In other words, all I want to be is the Jane Austen of south Alabama."